JPH02102003A - Molding method for tile of modified shape - Google Patents

Abstract

PURPOSE:To prevent a local part insufficient in the molding pressure from remaining in a tile body by forming a projecting part to a forming mold corresponding to the parts in which two different faces are crossed toward the inside in the side face of the tile and locally enhancing the molding pressure. CONSTITUTION:When the body 16 filled in a filling space 15 is pressurized by lowering a top force 17, the stress of molding pressure to the direction shown in the arrows A is caused toward the inside of the tile body from the outside thereof and the insufficiency of molding pressure due to the dispersion of stress is caused in the parts 12 wherein two different faces are crossed toward the inside. On the other hand, since a projecting part 19 is formed in the part of a bottom force 14 correspondent to the parts 12 wherein two different faces are crossed toward the inside, the molding pressure of the body 16 in the regions of these crossed parts 12 is made larger than the molding pressure of the body 16 in the other part. Therefore behavior of thermal expansion and contraction in a calcining stage is performed while keeping the whole tile body as one unit and is not partially performed and therefore a crack is not caused in the crossed parts 12.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an irregularly shaped tile in which a portion of one tile side surface is formed with a portion where two different surfaces intersect toward the inside, and the present invention provides zero stress dispersion during molding. This invention relates to a method for molding irregularly shaped tiles in which a convex portion is formed on the mold to partially increase the molding pressure to compensate for the lack of molding pressure caused by the molding.

[Conventional technology]

An example of a tile exhibiting a special decorative pattern is an irregularly shaped tile 1 as shown in FIG. This irregularly shaped tile 1 is
The opposing surfaces of the four circumferential side surfaces 1a to 1d are formed symmetrically, so that the uneven surfaces match each other when the construction is performed. Thus, on each of the four circumferential side surfaces 1a to 1d of this irregularly shaped tile 1, at least one portion 2 is formed where two different surfaces intersect inward.

The irregularly shaped tile 1 having such intersecting portions 2 is manufactured by dry molding since it is not possible to form irregularities on the four circumferential sides 1a to 1d by wet molding. In dry molding, normally, as shown in FIG. 5, a filling space 5 formed by a frame mold 3 and a lower mold 4 is filled with clay 6, and this is pressurized by an upper mold 7 to form a tile molded body. The product is obtained by applying a glaze and firing it.

By the way, the irregularly shaped tile 1 exhibiting such a special decorative pattern is used as a paving block by being attached to the surface side of a cement block or the like having the same shape, for example. By adhering the irregularly shaped tiles 1 to cement blocks, it is possible to improve the abrasion resistance and also to obtain a paved surface that is aesthetically excellent.

[Problem to be solved by the invention]

However, in such a dry molding method for irregularly shaped tiles 1, molding stress as shown in FIG. 6 is generated in the clay 6 when pressure is applied to the clay 6 by lowering the upper mold 7. This forming stress acts from the outside to the inside of the irregularly shaped tile l, and in a direction perpendicular to each of the circumferential sides 1a to 1d. Therefore, as shown in FIG. 6, stress is dispersed in different directions in a portion 2 where two different surfaces intersect inward, resulting in insufficient molding pressure for the clay in this portion. Therefore, when such a pressure-formed base body is fired, the behavior associated with thermal expansion and contraction of the tile is divided at the portion where the molding pressure is insufficient, and the behavior associated with thermal expansion and contraction occurs individually in each divided region. However, as shown in FIG. 6, there was a drawback that cracks 8 were generated at the intersecting portions 2.

[Means to solve the problem]

The present invention improves and eliminates the above-mentioned conventional problems, and provides a tile forming method that does not leave localized areas of insufficient molding pressure on the tile base during dry pressure forming of tiles. This is what I am trying to do.

Therefore, the means adopted by the present invention to solve the above problem is to provide an irregularly shaped tile in which a portion where two different surfaces intersect inwardly is formed on the side surface of one tile, and the intersecting portion A convex portion is formed on the molding surface of the mold corresponding to the back side of the mold, so that the molding pressure applied to the clay in the intersecting parts is higher than the molding pressure applied to the clay in the parts other than the intersecting parts, Insufficient molding pressure is compensated for by the dispersion of stress generated at the crossing portion from the outside of the tile to the inside of the tile during molding.

[For production]

Normally, when clay, which is a raw material for a tile base, is dry-press molded, the stress distribution of the forming pressure acting on the clay acts perpendicularly to each side of the tile base from the outside to the inside. Therefore, in the case of irregularly shaped tiles in which a portion of one tile side surface is formed where two different surfaces intersect inward, local stress dispersion occurs from the intersecting portion, resulting in insufficient molding pressure. .

Therefore, in the present invention, a convex part is formed in the mold corresponding to the intersecting part, so that the molding pressure acting on the clay at the intersecting part is higher than the molding pressure acting on the clay at other parts. That's what I do.

As a result, the forming pressure acting on the clay at the intersection is compensated for by the shortfall caused by the locally dispersed stress.
A uniform stress distribution of molding pressure can be obtained over the entire tile substrate. Therefore, during thermal expansion and contraction in the subsequent firing process, cracks will not occur at the portion where two different surfaces intersect inward.

〔Example〕

The molding method of the present invention will be described below based on examples shown in the drawings.

1 to 3 relate to one embodiment of the present invention, in which FIG. 1 is a partially enlarged vertical cross-sectional view of a mold, FIG. 2 is a bottom view of a irregularly shaped tile 11, and FIG. 3 is a view of the same tile. 11 is a side view of FIG. It should be noted that, as in the conventional case, the irregularly shaped tiles 11 of this embodiment are adhered to the surface side of a cement block or the like of the same shape and used as, for example, a paving block. As shown in FIGS. 2 and 3, the irregularly shaped tile 11 of this embodiment has the same planar shape as the conventional irregularly shaped tile 1 shown in FIG.
Each id is formed with a portion 12 where two different surfaces intersect inward. In this embodiment, as shown in FIG.
A convex portion 19 having an arcuate inner circumferential surface 19a when viewed from above is formed in a portion of the lower mold 14 corresponding to No. 2. The filling space 15 formed by the frame 13 and the lower mold 14 of such a mold is filled with 16 pieces of plastic material, which is the raw material for the tile base material.
By pressing and molding the clay by lowering the upper mold 17, as shown in FIGS. 2 and 3,
A four part 20 having an arc-shaped inner circumferential surface 20a is formed at a portion 12 where two different surfaces in the ie intersect inward.

In this way, the convex portions 19 are formed in the portions of the lower die 14 corresponding to the intersecting partial works 2 of the irregularly shaped tiles 11, and the intersecting portions 12 are press-molded with the clay 16, which is the raw material for the tile base material. It is possible to compensate for the lack of molding pressure by dispersing stress. This will be explained below. That is, as shown in FIG. 1, when the upper mold 17 is lowered and the clay 16 filled into the filling space 15 is pressurized, it moves from the outside of the tile base toward the inside as indicated by arrow A in FIG. A molding pressure stress is generated in the direction, and a molding pressure shortage occurs due to stress dispersion at the portion 12 where two different surfaces intersect inward. On the other hand, since a convex portion 19 is formed in the portion of the lower mold 14 corresponding to the portion 12 where two different surfaces intersect inward, the molding pressure of the area of the intersecting portion 12 is ±16. is thicker than the molding pressure of the clay 16 in other parts, and the increased molding pressure corresponds to the insufficient molding pressure due to stress dispersion generated in the intersecting part 12. Therefore,
The insufficient molding pressure at the intersecting portions 12 due to stress dispersion due to the molding pressure indicated by arrow A is compensated for by locally increasing the molding pressure at the intersecting portions 12 by forming the convex portions 19. Is possible. In this case, it should be noted that the inner circumferential surface 19a side of the convex portion 19 is formed in an arc shape when viewed from above, and
It is important that the stress of the molding pressure shown by is distributed in a direction perpendicular to the inner circumferential surface 19a so as not to be locally concentrated and dispersed.

Therefore, the tile base dry-formed as described above does not suffer from insufficient molding pressure due to stress dispersion at the portion 12 where two different surfaces intersect inward, and the thermal expansion and contraction during the firing process does not occur. Since the behavior is performed on the whole tile as a unit and not on parts,
No cracks will occur at the intersection 12.

The present invention is not limited to the embodiments described above, and can be modified as appropriate. For example, the shape of the irregularly shaped tiles 11 may be arbitrarily modified according to the purpose of decoration, and the shape of the irregularly shaped tiles 11 may be modified as desired depending on the purpose of decoration. The convex portion 19 of the mold may be formed on the upper mold.

〔Effect of the invention〕

As explained above, in the present invention, when molding an irregularly shaped tile having a portion on the side surface of one tile where two different surfaces intersect inward, the stress dispersion from the intersecting portion is This can be compensated and relieved by locally increased molding pressure, resulting in a uniform molding pressure stress distribution over the entire tile substrate. Therefore, in the subsequent firing step, no cracks will occur at the intersecting portions, that is, it is possible to significantly improve the yield.

[Brief explanation of drawings]

Figures 1 to 3 relate to one embodiment of the present invention, in which Figure 1 is a partially enlarged vertical cross-sectional view of a mold, Figure 2 is a bottom view of a irregularly shaped tile, and Figure 3 is a side view of the same. , Figures 4 to 6 relate to the prior art, where Figure 4 is a plan view of an irregularly shaped tile, Figure 5 is a vertical cross-sectional view of a mold, and Figure 6 is a tile showing the stress distribution during molding. It is a partially enlarged view of a molded base material. 11... Irregular tile 11a to lid... Tile side surface 12... Intersecting portion 14... Lower mold 19...
convex part

Claims (1)

[Claims] 1. An irregularly shaped tile in which a part is formed on the side surface of one tile where two different faces intersect inward, and a convex part is formed on the molding surface of the mold corresponding to the back side of the intersecting part. , the molding pressure that presses the clay at the intersection is
The molding pressure is set to be higher than the molding pressure applied to the clay other than the intersecting parts, and the insufficient molding pressure due to the dispersion of stress generated at the intersecting parts from the outside of the tile toward the inside of the tile during molding is compensated for. A method for forming irregularly shaped tiles.